


The Genocide Runs

by Novellarisia



Series: Game Master [2]
Category: Undertale (Video Game)
Genre: F/M, Reader Is Not Chara, Reader Is Not Frisk, reader is female
Language: English
Status: In-Progress
Published: 2018-01-10
Updated: 2018-12-10
Packaged: 2019-02-13 04:11:05
Rating: Not Rated
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 4
Words: 5,487
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12975588
Author URL: https://archiveofourown.org/users/Novellarisia/pseuds/Novellarisia
Summary: Sans finally meets you.





	1. So it Begins

\- Sans POV -

Sans woke up with a start. C***! He knew the kid would reset. Especially when they lost because of interference. What were you even doing here? Not to mention why did he even dream of you? So many questions with no way to get them answered. 

"SANS, YOU LAZYBONES, WAKE UP! BREAKFAST IS READY!" 

Good ol' paps. Welp he should probably head down, before Papyrus comes up. Lazily he got up and threw on his blue hooded jacket. He plastered on a smile and headed downstairs. As soon as he sat down at the table he took one look at the burnt, runny, glittery mess on his plate and strategically sent it to the void. Pappy's spaghetti always made him cringe, but he held back to spare his brother. Keeping paps happy and was always first priority. 

"SANS! HURRY TO WORK, OR YOU WILL BE LATE. ALSO YOU STILL NEED TO RE CALIBRATE YOUR PUZZLES." 

"sure thing bro." He looked at his brother for another moment, to burn this image again into his memories. Then watched as his brother left before him. 

After taking another moment to gather himself, he teleported to his station by the ruins. He knew the kid wasn't due to show up until at least tomorrow, but he needed to think. Particularly about the last time line. How did you get there? Did it have something to do with that crazy dream? 

He was just about to sit down when he heard something. A soft groan was coming from behind him. Quickly he turned into a defensive position, when he froze. There at the edge of the tree line was you. He couldn't believe it. You are not only in the underground but you started at his century station. 

When he saw you begin to stir he shook his head to clear his mind. He would help you, make sure you were ok, then he would get some answers.

\- (Y/N) POV -

You woke up cold and with a headache. Is this what death is like? You gave a small groan as you shifted in the snow to get up. Once you sat up you looked down to see the wound, but it wasn't there. Why not?! Was it a dream? That's when you heard snow crunching ahead of you. When you looked up you were surprised to see Sans walking calmly towards you. You made a move to stand up, but your legs felt like jelly. Unfortunately you only managed to make a thorough mess of the snow around you.

"hey buddy, you ok there?"

You looked up to see concern and amusement in his eye sockets. He was really close to your face. He had squatted down to get eye level with you, and you had to admit that he was much cuter in person. You immediately felt your face heat up, and quickly averted your eyes.

"I-I think so. I just can't get my legs to work."

Why did you just tell him that!? You tried to stand again, when you felt his hand grab your arm to help you up. For a moment it was hard to get your feet under you, but finally you were able to stand. You lock your knees and knew that walking was going to be impossible for a while.

"Thank you"

"heh, snow problem kiddo."

You immediately let out a giggle. While you weren't that great at making puns, you did love them when you caught them.

"i'm sans. sans the skeleton, and you?"

"(Y/N)" You replied while reaching for his offered hand. You knew it was coming and prepared a comment for him. The moment you heard the fart noise you laughed.

"Wow dude didn't know you had it in you."

The look on his face was priceless. You knew that he was about to tell you it was a classic, but having the joke turned around on him left him speechless. He broke into a big smile, well bigger since he usually shows a smile. Slowly he shook his head as he placed both hands into the pockets of his blue hoodie.

"heheh. gotta admit i didn't expect to have my own prank turned around on me. you're pretty good."

"Well I try." You smiled. It was really cold out and the wind had picked up. You shivered lightly trying to keep what little warmth you had left.

"hey you ok? you seem a little chilled to the bone."

You were about to reply when you realized he used another pun. You huffed out a laugh.

"Yeah didn't mean to give you the cold shoulder, but I wasn't expecting such an icy reception."

He immediately let out a deep heartfelt bellow of laughter. Bent the way he was you couldn't see the tears of joy gathering in his eyes.

"that was a good one kid. hey why don't you come to my place, to warm up? it will be a lot more comfortable to talk than out here." He said gesturing to the forest around you.

You clench your teeth to keep from chattering and nod your head. He placed his hands back into the pockets of his hoodie and began walking back to his station. Tentatively you made a move to follow him. Shifting your weight from one leg to the other however was a bad idea. The moment you tried, your legs gave out and you found yourself right back in the snow, with a small yelp. Sans must have heard you, because his head whipped around and the next thing you knew he's standing in front of you again.

"what happened?"

"Sorry" you said between pants. somehow your breathing had become heavier and it felt like you had run a marathon. You looked up at Sans and suddenly felt dizzy. You closed your eyes and felt the rest of your strength give.

"whoa! buddy you ok? buddy? hey (Y/N)?!"

You felt him shake you progressively harder just before you passed out.


	2. Questions

**Summary for the Chapter:**

> Sans learns a little about you, and adds to his growing list of questions. Also you finally grasp your situation.

On his knees in the snow he held your limp form. When he looked down at you a shiver trailed down his spine. It reminded him too much of that last time line. The only difference, you're not dying. Or… were you? Quickly he brought his hand to your chest and slowly coaxed your soul out. The moment it left your body the entire area was bathed in green and silver light.

It looked just like his dream, a beautiful emerald green wrapped in beautiful silver lines.They seemed to flow in intricate patterns, yet never overwhelmed the green. It was dimmer than he remembered though. Shaking himself out of his trance, he quickly checked your stats.

LV 0  
HP 05/100  
DF 01  
ATK 01

To say he was shocked was an understatement. First you had no LV. None! The lowest he has ever seen is LV 01, and that is when they have never hurt or killed anyone. Even a baby is born with LV 01. Does this mean that you don't even have the potential to hurt anyone?

Then there's the matter of your HP. A reset should have healed your wounds and filled your stats. Plus looking at your soul there doesn't seem to be… no there it is. A small scar, hidden amongst the silver patterns. Still your HP shouldn't have been so low. You needed food.

With that thought he carefully placed your soul back into your body and picked you up bridal style. You weighed practically nothing. This startled him as well, because when he stood he staggered trying to regain his balance from the lack of weight. He stood for a moment looking at you. More questions sprung to his mind, but he would have to wait for the answers.

With his magic he opened a shortcut home and stepped through. He looked around to make sure that Papyrus wasn't home before he walked to the couch and set you down. You had only been unconscious for a few minutes, so he went to the kitchen and grabbed some monster candy. Coming back into the living room, he wondered how he would get you to eat it. If he just put it in your mouth you might swallow it and choke. He decided to break it into smaller pieces. He manifested a bone and, setting the candy on the dining table, smashed it into smaller pieces.

He gathered the magical pieces and brought them to the couch. Gently he took your jaw in one hand and pried your mouth open. He placed a piece on your tongue and closed your mouth. Now it was just a matter of time before you woke up and he got answers.

\- (Y/N) POV -

It felt warmer than you remembered. Slowly you opened your eyes. This was not Snowdin forest. For a second you thought that everything might have been a dream, until you saw a sleeping skeleton in a blue hoodie sitting on the other end of the couch. You blink trying to bring everything into focus. You find that you are on the skeleton brother's couch, in their house. You'll admit that it looks different from the game, but only because this is real. It's not 2D graphics on a screen or a drawing on a page. You turn your head to the left and see a television. Just above it is railing to an open second story. Then to the left is the stairs leading to the second story. Looking at Sans to make sure he still asleep, you face the ceiling and taken moment to let everything sink in.

You're in Undertale. You somehow got here after trying to correct Justin's genocide run. You managed to get to Judgment Hall, just in time to save Sans from Chara. CHARA!! She nearly killed you then… or did you die? You can't remember. Just a faint memory of sands saying 'thanks'. Was that even real? Now what? Are you trapped here until the monsters get free? Will carra be in the time line to? You can only assume it's a new timeline because you're not hurt, but why were you so weak? What's happened to you?

Suddenly bony hands were gently shaking you. You could hear his voice but you couldn't make out what he's saying. Why was it so hard to breathe. C***! You're hyper ventilating. You held your breath for a moment and let it out slowly. You breathed in-and-out. Now you could start to hear Sans.

" that's it just breathe. in-and-out. there we go. you're ok. your safe. just keep breathing."

His voice was really soothing and helped calm you down. Once you've calmed down, Sans moved back a little, away from the couch. Feeling awkward you moved to sit up. Sans was quick to help you.

" easy there buddy. your hp isn't full yet. here suck on this. its monster candy. it will bring your hp up quicker."

" Thank you."

"heh no problem kid. wanna talk about it?"

" I… just freaked out. I'm sorry. I don't usually do that." You avert your eyes. As much as being here with him is amazing, you don't want to die. Though if you're being honest with yourself it's not Chara or death that scares you. Your body being weak for no apparent reason is what's scary. " I don't know what's happening to me." You say in a small voice.

"then maybe you and i can figure it out together."

You lift your eyes to meet his. Is he serious? He wants to help you? Maybe… this is his way of figuring you out? Well in any case the result is still the same. You smile.

"Ok."

"let's start by having you answer some questions. ok?"

"Ok."

"first where did you come from... er... i mean how did you get here. in the underground."

" I'm not sure if you would believe me."

"try me."

So you told him about your friend Justin and the game. All through your story you watched Sans carefully. For being a skeleton his face was very expressive, just like a human's. You waited for him to completely close himself off, or become angry and claim that you had lied. You did not expect recognition.

" After that I hit the button to agree to Flowey's terms, so that I could make everything right. The last thing I remember before waking up in the underground, is the color green. I hope that helped."

Sans expression was unreadable. He was quiet for a while, then he let out a loud and humorless laugh.

"so we are just part of a game? no wonder it never ends."

" Actually I don't think this is a game."

" _what?_ you just told me that you played a game and that's how you knew me. _because you became friends with my character **in a freaking game!**_ "

" Yes everything I told you is true, but this doesn't feel any different from, for lack of a better term, my world. Don't you think that someone from a non game world would be able to tell some kind of difference?"

He doesn't answer.

" I think it's more likely that the game was a portal to the underground. Maybe I'm just the first one that wanted to fix a genocide run. The game itself is relatively new, so it's possible that I'm just the first of many."

"maybe." He conceded. This at least made his eye lights a little brighter.

" May I ask you a question?"

"you just did." He smirked.

You chuckled. OK yeah that was a good one. "Ok you got me."

He chuckled. "what's your question buddy?"

" In the last time line… did I… die?"

His smile faded. "no. it was close, but the kid RESET before you did."

You glanced outside and realized it's starting to get darker. Sans noticed your gaze drawn to the window. Suddenly he picked you up and with a blink you're in a messy bedroom. He placed you on the bed.

"sorry, but my bro will be home soon. he can't know your here. i will be back with more food and monster candy. i think that should be enough to bring your hp back up."

" Is that why I felt so weak in the forest? Low HP?"

"yeah. though why it's taking so long for you to recover is a mystery. don't worry though we'll figure this out." With that he took a shortcut and disappeared.


	3. Chapter 3

\- Sans POV -

Sans appeared downstairs just as his brother came through the door.

"SANS! YOUR HOME ALREADY?! DON'T TELL ME YOU SPENT ALL DAY HERE?"

"nah bro. just got home a bit ago."

"OH! GOOD! THEN I WILL GET DINNER READY!"

"sounds good." Sans then takes a seat on the couch melding with it. Everything that you told him still bouncing in his head. Could she be right? Could she be the first of many? There is just one thing though. To get there they have to be willing to kill and complete, what did she call it? A genocide run. Those are not the types of humans he's intrested in meeting. The fact that his life is seen as a game also doesn't sit well with him. Could that be why they're doing this? Does the kid see this as a game, and think they can get home if they kill everyone?!

Maybe. But he won't find out unless he can get the kid to talk. D***! His thoughts then drift back to you. If you and the kid got here the same way, then why were you so different? He was concerned that it was taking so long for your HP to replenish. You were out for a good 8 hours, and while he did notice it speed up, you only recovered half. There has got to be a logical reason. You need actual food though. Unfortunately Paps' spaghetti might do more harm than good, and he needs your help. He's not sure why, but he knows you're important to stopping the RESETS.

He gets up from the couch and peeks into the kitchen. Paps is hard at work making dinner. Quickly while his brother is busy he takes a 'shortcut' over to Grillby's. Stepping through the door he is immediately greeted by everyone. It feels good to have so many look forward to seeing him. For just a moment he can forget the kid and all the horror that is sure to follow when they arrive. The moment he sits down at his usual place at the bar, he finds Grillby already there with a bottle of ketchup.

"can't stay tonight grills. just need two fries to go."

Grillby lifted an eyebrow at this, but said nothing. Instead he gave a brief nod and headed to the kitchen to make the order. Sans couldn't stop thinking about what it meant that you were here. It doesn't help to go over the same thing again and again without new information. He'll just have to wait. At least he now knows that what he saw in his dream was real. Now another question how is that possible? 

Sans shakes his head. This train of thought is getting him nowhere. Grillby comes out with a bag, and hands it to him.

"thanks grills. put it on my tab."

Grillby does his version of an eye roll and lets out a huff of sparks. Sans chuckles under his breath and quickly takes a 'shortcut' to his room. The moment he steps inside something seems off. First it's dark, which he expected. Then he realizes he expected you to be sitting on his bed, waiting for him. You're not though. Your sleep again. This has him nervous for a moment. He comes to the side of the bed and gently places his hand on your shoulder.

"hey buddy, wake up. i brought you food and you need to eat."

He watches as you slowly rouse from your sleep. He needs to check your stats again, but that can wait till tomorrow.

"Mmm. That smells good."

Your voice was a little rough, and it sent a shiver down his spine. He liked that. He had to admit you were gorgeous. Something about you pulled at his soul, but now is not the time to think about it.

"yeah. thought you might appreciate grillby's instead of my bro's spaghetti."

"Thank you." You smiled at him, and it lit up the room. It was beautiful. Sans had to tear his eyes away so that he couldn hand you the food. After giving you a box of fries he stands up to head back downstairs.

"after you finish eating, go ahead and go back to sleep. hopefully your hp will be fully restored by tomorrow. if it is i'll take you with me to work."

"OK. Thank you again Sans."

"heh. no problem." With that he closed the door and went to join his brother.

\- (Y/N) -

Once you saw Sans leave, you began to work on the fries he had given you. They were better than you imagined them to be. You had read the fan fictions about how Grillby's is supposed to taste. No offense to any writers, but no one could have even come close to how heavenly they taste. It felt like you had just started to eat, but when you look down they were gone. You would have thought someone stole them, but you felt full and no one else was in the room. You almost felt sad for the loss. At least you were feeling stronger now. You looked out the window and saw that it was dark. If you were home you would have said it was night. You went to the window and looked up. There were no stars. For a moment it felt stifling. You went back to the bed and laid down. Tomorrow would be better right? Right.

The next morning came to early. You are vaguely aware that you were not in your room, and that something felt off. You are forgetting something. Something important. Just then your eyes flew open and you practically launch yourself out of the bed. Work! You were going to be late! The blankets decided to capture and hold your feet hostage. Which ended with you sprawled face down on the floor. You heard a deep chuckle come from behind. 

"just waking up and already you're falling for me."

It took you a moment to register what was said. You look behind you and saw Sans standing in the doorway with a shit eating grin on. It was in that moment that all of yesterday came flooding back to you. Looking at him you smiled.

"I would say it was a pleasure, but I didn't realize I would fall so hard." She said tapping the floor for emphasis. He let out a hearty laugh and stepped into the room. You decided to clamber off the floor. Once you got your feet untangled you started to get up.

You felt sans grab your arm to help you up. You were hyper aware of his hand. Where every phalange was placed, the strength of his grip, even how warm he felt on your arm. It only lasted a moment, so when he released his grip, you already missed the contact. He had you sit on the bed, and he sat beside you. He turned toward you and looked into your eyes as he spoke.

"i need to check your stats. in order to do that I need to bring your soul out."

"OK."

"ok? just like that!? you know what your soul is don't you? it's the very culmination of your being. this won't be like your game. even though I'm only checking your stats this will feel… intimate." He started blushing.

"I thought maybe. I trust you Sans. I trust you not to hurt me or be inappropriate."

He looked at you for a moment mouth slack. You could tell that what you said surprised him. After all you had technically only met yesterday.

Blinking twice you watched his jaw firm up in what can only be described as determination, and brought his hand towards your chest. You couldn't help the small blush dusting your face, when you took note how close his phalanges were to your breasts. He stared into your eyes, as he twisted his hand slightly and slowly drew it away. You felt something gathering at the spot his hand was and slowly move to follow. It wasn't painful, but you began to feel light headed and week. You saw the green and silver heart before you, and were in awe. You almost couldn't believe that was you because it was so beautiful. You almost couldn't get enough of looking at it. Finally you were able to drag your eyes away, to see that Sans was still watching you. Once he saw that he had your attention, he looked at your soul. You thought you saw his gaze soften, but it was only for a moment. It was another moment before he slowly eased your soul back in. Once it was completely inside a wave of dizziness hit and dissipated, and your strength returned.

"your hp is full. i'm going to bring you to my post by the ruins. chara is due to show up today." Your face must have paled, because he hurriedly continued. "don't worry. as long as you stay hidden she shouldn't do anything."

You nodded. He then stood up and walked over to his closet. He grabbed another blue hoodie and tossed it to you. You looked at him a little confused when you caught it.

"put it on. it should keep you warmer than what you're wearing."

Raising an eyebrow you looked down at yourself. Sure enough you were wearing a cap sleeved, V neck shirt and flared pants. Both the shirt and pants were a dark emerald green color. The top was long almost like a mini dress and had silver patterned stitching along the bottom hemline, sleeves, and neckline. You were also wearing a wide silver belt around your waist emphasizing your curves. Looking it over again the colors and patterns of your outfit, kind of reminded you of your soul. Huh. Talk about coincidence.

You quickly put on the borrowed hoodie and stood to follow Sans. He saw you were ready and held out his hand.

"it will be quicker to take a 'short cut', 'cause were already running behind."

Understanding dawned on you, and you quickly took his hand. Remembering all your fan fics you quickly closed your eyes before he said anything. You waited in anticipation for that sign of weightlessness, or feeling the floor drop from beneath you.

"we're here."

Nothing... just sudden cold shooting down your neck. You don't even feel disoriented. What a disappointment. It must have shown on your face, because his eyes lit up with amusement as he chuckled.

"what? not what you were expecting?"

"No." You nearly pouted. Nearly. Because pouting is childish, and you're not a child.

"heheheh ok. go hide behind those trees over there. the ruins haven't opened yet and they should show up anytime now."

With a nod you quickly ducked behind the tree, as Sans vanished. You waited trying not to let thoughts of Chara overwhelm you. She nearly killed you once. Of course you did jump in front of her attack. What else were you to do though. You're not a fighter. Not sure if you even could be. Plus it's not like she hurt you on purpose. She was after Sans. You looked at the door to the ruins in frustration. _Where is she?_ You sighed heavily. To quote one of your favorite books 'Patience is not my virtue.'

Your legs were starting to cramp from your position. You were just about to stand when you heard something. It sounded like a big latch being undone. Several minutes later the door began to move. You held your breath, as you watched the door open wider. _Maybe it's Frisk this time._ When the door stopped moving a small hand in a blue sweater reached out and grabbed the edge of the door.


	4. Chapter 4

**Notes for the Chapter:**

> Sorry this was a long time coming. I guess this is what happens when you have too many things going on. Lol
> 
> Hope you all enjoy, and please leave a comment and let me know what you think.

You held your breath, as the child made their way through the door. You saw more of the sweater. It was blue and pink. _Yes! It's Frisk!_ You let out a sigh of relief. When they stepped through completely, however, you sucked in a breath of surprise. The dusty cloud that followed them, their dusty clothes, and worst of all their red eyes. This wasn't Frisk. This was Chara.

A few tears began to form in your eyes, as you realized that some of that dust belonged to Toriel. Memories of befriending her in the game flooded your mind. This was real, and they just killed one of the most gentle monsters in the underground. The moment that they stepped through, they looked around. A creepy smile spread across their face.

" _Oh Sans_ ~ I know you can hear me. We both know I would have won, before we were so rudely interrupted. I have a firm grip on Frisk this time too, so don't count on any help coming this time.

As they spoke they walked down the path toward Sans post. You listened knowing that things would be different, but Chara didn't know that yet.

You waited until you couldn't hear them anymore, before you began to follow them. You watched as Sans broke the huge branch. (Sorry you couldn't call something that big and that thick a stick.) You kept watching as they 'met' him, and Papyrus for the first time. Unless they spared him, it made you sick to know that he would die.

Somehow Sans knew right where you were and took a 'shortcut' to your location. He didn't have a smile on like usual. You knew that he knew what was going to happen to his brother. You could feel the sadness, anger, and helplessness pouring off him. You started imagining what it would be like to see your little brother, that you practically raised from a baby, die at someone's hands again, and again, and again with no end in sight. Once you began picturing it you couldn't stop it. The tears that had begun to form because of Toriel's death, fell from your eyes unrestrained.

You felt a hand gently cup your cheek and lift your face slightly. Slowly you began to focus on the monster in front of you. Sans gently ran his thumb under your eye wiping away some of the tears. Once your focus was fully back to reality you saw blue tears had begun to form in his sockets, with dimmed eyelights.

"I know the feeling kiddo. come. we have some time to form a game plan before they officially meet my bro."

"Can't we save him?"

Sans paused before he slowly shook his head.

"if we try, they'll just reset."

You slowly nod your head. He's right, they more than likely would, but it might be worth it. To you at least. It's in that moment that you vow to save Papyrus or at least try. Maybe that's why you're here, to be a shield. You may not like dying, but you would for these monsters.

~Sans POV~

The moment the kid exited the ruins, he knew Chara was in control. He struggled so hard to not kill them on the spot. He ground his teeth as he listened to them. Bragging about the nightmare they bring to the underground.

He followed them and 'played his part', but when he got a moment to look away he went to check on you. Somehow you stayed quiet as you followed them. He saw when you recognized an action or a phrase, but he also saw your emotional struggle. He saw the look on your face when you watched the dust fall from the kid. He also noted how hard you were trying to keep your tears in check.

After the kid had met Papyrus, and gone off on their own, Sans headed back to you. You were crying. He didn't know why he was surprised. After all he had the same emotions run through him every time Chara or Frisk met his brother. Remembering every single time that his brother died in front of him. Knowing that no matter what he tried nothing would change. 

He had an overwhelming urge to comfort you in that moment. He reached his hand to gently cup your cheek. He moved his thumb to wipe the tears from your eyes. Hoping that you would come to your senses soon. He watched your eyes, and slowly he felt himself lose control over his own emotions. It was at that moment that he noticed that your focus was purely on him now. Whatever dark place you had fallen into, you had resurfaced to see him cry.

"I know the feeling kiddo. come. we have some time to form a game plan before they officially meet my bro.

"Can't we save him?"

Sans took a moment to really look at you. Why he was surprised about your concern for his brother, he didn't know. You seemed to really care, yet you had never met any of them before. Not really. In your world him, his brother, and every monster down here were just part of a game. A game where you could choose to befriend them, or... kill them. Maybe there was something more to you than meets the eye. Whatever it was he didn't have time to figure it out now. He then slowly shook his head.

"if we try, they'll just reset."

He watched as you took a moment to process his words. He found himself fascinated by you. Whatever you were thinking about, allowed your eyes to dry and mouth to set. There was even an instant where your eyes flashed a bright, deep green. The same color as your soul. It was so quick however that he wondered if he truly saw it at all.

It was at that moment that you moved toward him. He reached out his hand and took yours then cut a 'shortcut' into his living room. You went straight over to the couch and sat down. Sans hesitated. They both knew so little of what was going on. He knew in his soul that you were the key to ending the RESETS. The problem was, he didn't know how. With a feeling of defeat he walked over to the couch and slumped down. After a few moments he opened his mouth to tell you that he had no idea what to do, when you spoke.

"I need to be there when Papyrus fights Chara."

He was not expecting that.


End file.
